In a bowl, soak the dry Azuki beans with a generous quantity of water overnight.

Drain the water with a strainer. Then put the Azuki beans in a pot and fill the pot with water until the water level is 2-3 cm above the Azuki beans, covering them completely. Cook at high heat until it boils.

Drain the boiled water with a strainer. Again, put the Azuki beans in a pot and fill the pot with water until the water level is 2-3 cm above the Azuki beans. Cook at high heat until it boils. Once it starts to boil, cook on low heat until the Azuki beans are fully cooked. This usually takes about 1 hour, but you can try one or mash with your finger to check and see if the beans are soft and finished cooking.

Add the sugar and mix gently. Cook on low heat to remove the excess moisture.

Put the mixture into a food processor and mix for about 3 minutes. If you prefer smoother Anko, you may extend the mixing time in the food processor.